1. Field of the Invention
This invention relates to a hair dye composition capable of dyeing the hair by applying it to the hair.
2. Description of the Prior Art
Most of known hair dyes comprise oxidation dyes such as p-phenylenediamine, p-aminophenol or resorcinol as an active ingredient. It is indispensable to use an oxidizing agent in using such a conventional oxidation hair dye. Thus these hair dyes contain peroxides such as hydrogen peroxide or perborates. Furthermore, conventional oxidation hair dyes contain basic compounds such as ammonia or monoethanolamine in order to promote swelling of the hair and decomposition of the peroxides.
However the above-mentioned oxidizing agents and basic compounds suffer from some troubles that they would irritate the skin, eyes or scalp and that they would make the hair brittle because they cleave chemical bonds of cystine as a constituent of the hair so as to give damage to the hair.
Therefore Japanese Patent Laid-Open No. 104739/1978 and No. 104741/1978 proposed to dye the hair with the use of a cysteine derivative together with a dye.
However each of these attempts gives unsatisfactory "dyeing properties" and "shampoo-fastness".
On the other hand, so-called temporary dyes comprising direct dyes (nonpolymeric dyes) such as acid dyes or basic dyes are mild to the hair and skin. However, consumers are not satisfied with these dyes, since they show insufficient dyeing properties or suffer from considerable decoloring once shampooed.